LiNi1-yCoyO2(0.1≤ y≤0.4) positive electrode materials are synthesized by a chemical method with stoichiometric acetates of related cations. Their crystal structure, stoichiometry and electrochemical behaviors versus Co concentration are investigated by x-ray diffraction, synchrotron-based x-ray absorption fine structure and galvanostatic cycling measurements. The results reveal that the non-stoichiometric Ni2+, Li/Ni cation mixing and polarization are reduced as the amount of Co substitution increases, clearly indicating that the Co element is a medium for easily oxidizing Ni2+ to Ni3+ during the synthesis process.
LiNi1-yCoyO2(0.1≤ y≤0.4) positive electrode materials are synthesized by a chemical method with stoichiometric acetates of related cations. Their crystal structure, stoichiometry and electrochemical behaviors versus Co concentration are investigated by x-ray diffraction, synchrotron-based x-ray absorption fine structure and galvanostatic cycling measurements. The results reveal that the non-stoichiometric Ni2+, Li/Ni cation mixing and polarization are reduced as the amount of Co substitution increases, clearly indicating that the Co element is a medium for easily oxidizing Ni2+ to Ni3+ during the synthesis process.
XIA Rong-Sen;CUI Zhong-Hui;LIU Bi-Qiu;GUO Xiang-Xin;ZHAO Jing-Tai. Evolutions of Crystal Structure, Stoichiometry and Electrochemical Behavior with Co Substitution in LiNi1-yCoyO2 Positive Electrodes[J]. 中国物理快报, 2010, 27(7): 76102-076102.
XIA Rong-Sen, CUI Zhong-Hui, LIU Bi-Qiu, GUO Xiang-Xin, ZHAO Jing-Tai. Evolutions of Crystal Structure, Stoichiometry and Electrochemical Behavior with Co Substitution in LiNi1-yCoyO2 Positive Electrodes. Chin. Phys. Lett., 2010, 27(7): 76102-076102.
[1] Armand M and Tarascon J M 2008 Nature 451 652 [2] Tarascon J M and Armand M 2001 Nature 414 359 [3] Li H, Wang Z X, Chen L Q and Huang X J 2009 Adv. Mater. 21 4593 [4] Maier J 2005 Nature Mater. 4 805 [5] Guo Y G, Hu J S and Wan L J 2008 Adv. Mater. 20 4384 [6] Ellis B L, Lee K T and Nazar L F 2010 Chem. Mater. 22 691 and references therein [7] Ouyang C Y, Wang D Y, Shi S Q, Wang Z X, Li H, Huang X J and Chen L Q, 2006 Chin. Phys. Lett. 23 61 [8] Delmas C, Menetrier M, Croguennec L, Saadoune I, Rougier A, Pouillerie C, Prado G, Grune M and Fournes L 1999 Electrochim. Acta 45 243 [9] Lin Z P, Zhao Y J and Zhao Y M 2009 Chin. Phys. Lett. 26 038202 [10] McBreen J 2009 J. Solid State Electrochem. 13 105 [11] Delmas C and Saadoune I 1992 Solid State Ionics 53 370 [12] Zhecheva E and Stoyanova R 1993 Solid State Ionics 66 143 [13] Saadoune I and Delmas C 1996 J. Mater. Chem. 6 193 [14] Rougier A, Saadoune I, Gravereau P, Willmann P and Delmas C 1996 Solid State Ionics 90 83 [15] Ohzuku T and Makimura Y 2001 Chem. Lett. 8 744 [16] Cho J P, Jung H S, Park H J, Kim G B and Lim H S 2000 J. Electrochem. Soc. Am. 147 15 [17] Ravel B and Newville M 2005 J. Synchrotron Radiation 12 537 [18] Nakai I and Nakagome T 1998 Electrochem. Solid State Lett. 1 259 [19] Johnson C S and Kropf A J 2002 Electrochim. Acta 47 3187
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